The finding comes from a meta-analysis reported in Fertility and Sterility online February 27. “Possible mechanisms for the improved implantation and clinical pregnancy seen in this study are increased oocyte competence or improved endometrial receptivity,” the authors suggest, because supplementing LH did not increase oocyte yield.
Dr. Eric D. Levens, with the National Institute of Child Health and Human Development in Bethesda, Maryland, and colleagues explain that most normogonadotropic patients undergoing assisted reproductive techniques (ART) have sufficient endogenous LH levels to drive adequate ovarian steroidogenesis, and several studies have failed to show a benefit from adding recombinant LH to the ovarian hyperstimulation protocol in the general ART population.
“However, patients of advanced age who undergo ART likely comprise a larger proportion of poor responders, among whom the addition of LH may be beneficial,” they suggest.
To synthesize the available evidence on this issue, the team identified seven randomized controlled trials in which patients 35 years of age and older were treated with recombinant LH and FSH or FSH only for controlled ovarian hyperstimulation in a total of 902 ART cycles.
Most of the trials reported no difference in oocyte yield or in fertilization rates, the authors report. However, analysis of the pooled data indicated a significantly increased implantation rate in the LH group compared to the FSH-only group (odds ratio 1.36). The clinical pregnancy rate was similarly increased in the LH group (OR 1.37), the team found.
“As patients age, there is an increase in early follicular phase FSH but not LH,” Dr. Levens and colleagues note. “It is possible that the administration of LH restores the follicular milieu of the developing follicle in older ART patients.”
While concluding that the use of recombinant LH in this setting improves ART outcomes, they add, “More studies are needed to determine whether this effect exists in both GnRH agonist and antagonist protocols.”
Fertil Steril 2012.